But if they have changed their encryption techniques in recent versions of the iPhone's OS and hardware, then it might not now be possible for them to comply with an order that, in previous versions, may have been feasible on a one-off basis. In other words, perhaps the newer security measures they've introduced make it unfeasible to decrypt the phone without fundamental changes to the OS that would introduce a backdoor to everyone's iPhone, and maybe this wasn't always the case. I don't know whether this is true - can any Apple experts cast light on this?